Abstract: The measurement of segregation, the understanding of its drivers, and the effects of segregation are three interrelated issues that receive ample attention on both sides of the Atlantic. The comparative study of these subjects in Europe is not an easy task because the continent is highly fragmented and diversified. This regards the types of welfare state, but also the multitude of urban histories. Consequently, there is a lack of uniform information. Nevertheless, this paper makes an attempt to sketch the variety of ethnic and social segregation within Europe, using a large number of sources. It is shown that generally segregation levels in Europe are more moderate compared to what we can find in American cities, but these differences are not absolute. The paper also links the levels of segregation with a range of potential explanations and provides a window on European research focusing on effects of segregation.